In endoscopic and conventional medical procedures, surfaces must be joined or durably mechanically connected. For example, openings are closed, or vessels, tendons, or nerves are bound to one another. For some time sutures were exclusively produced by needle and thread for this purpose. Modern processes include tissue welding and tissue soldering.
To solder tissue, for instance, a synthetic material that is degradable in the body (also referred to as a biopolymer) is used as a solder. The solder has a melting temperature that lies above the body temperature in a temperature range at which tissue damage is only temporary or avoided altogether. To heat the solder, infrared radiation is used that is absorbed by the tissue only in small quantities and therefore heats the tissue only to a small degree. The infrared radiation absorbed in the solder heats the solder. The solder melts, moistens the surfaces that are to be joined or mechanically connected, and connects them in a mechanically durable manner after cooling below the melting temperature and congealing, at least until the formation of mechanically load-bearing scar tissue.
Similarly to other soldering methods, the soldering temperature must be controlled precisely. The temperature of the solder and the temperature of the surfaces to be moistened must exceed the melting temperature of the solder, so that the solder completely moistens the surfaces that are to be moistened. The temperature of the bordering tissue may not be so high that the tissue is permanently damaged, or in particular becomes inflamed or dies off.
Unlike with soldering of electrical or electronic components, for instance, the remaining temperature range is relatively small. In addition, the absorbed infrared capacity and the achieved temperature depend on several parameters that are difficult to acquire or control and can vary strongly. These include water or moisture content of the tissue; the distance of the infrared source and the infrared intensity at the site of juncture, especially with endoscopic applications; and the thickness of the solder, which essentially conducts heat more poorly than does metallic solder used in electricity and electronics. In addition, the melting of the solder is often very difficult to recognize optically. It is therefore desirable to have an improved control or regulation of temperatures while soldering.
One object of the present invention is to provide an improved method for adhesive bond joining of two surfaces, an improved solder, a control device for controlling a adhesive bond joining of two surfaces, and a device for adhesive bond joining of two surfaces.